If it was done the same way as the Belsavis Dailies you might have an issue - having so many level 50s on a level 40-44 planet can be an issue on PvP servers (can you spell "gank" anyone?). That being said, I like the BH District dailies because everyone's 50 so there's no picking on the lowbies.
I think maybe adding another area like the BH District on some of the planets - Nar Shaddaa, Tatooine, Alderaan, Hoth, Belsavis, and lastly Voss would be nice.
I think this is a great idea. Having a high level playground like the Black Hole on every planet would be awesome.